Optical instrument.



E. J. BRGWN. OPTICAL INSTRUMENT. APPLICATION FILED JUNE 20, 1.910.

987,951, Patented Mar.28,1911'.

2 SHEETS-SHEET 1.

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THE NoRms PETERS cv.. wAsmNuraN, D. c.

E. J. BROWN.

OPTICAL INSTRUMENT.

APPLIOATION FILED JUNE'zo, 1910.

Patented' 111211228, 1911.

2 SHEETS-SHEET 2.

1HE NoRRls PETERS co., wAsNlmrraN, D. c,

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EARL J'. BROWN, 0F CHICAGO, ILLINOIS, ASSIGNOR T0 FRED GERLACI-I, TRUSTEE, OF CHICAGO, ILLINOIS.

OPTICAL INSTRUMENT.

Specification of Letters Patent.

Patented Mar. 28, 1911.

To all whom it may concern,.-

Be it known that I, EARL J. BROWN, a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Optical Instruments, of which the following is a full, clear, and exact description.

In retinoscopy or shadow tests,7 it is now common practice to employ a mirror or reflector having a peep-hole therein which is pivotally mounted so it may be rocked or tilted and is rotatably sustained so that the axis about which the mirror tilts, may be varied to correspondingly vary the plane of movement for the determination of refractive errors in eyes.

Gne of the primary objects of the invention is to provide an improved retinoscope, in which the necessity of tiltably and rotatably mounting the mirror will be avoided, so that any inaccuracies, which might result from variation of the position of the reflector or mirror due to its pivotal and rotatable mounting, will be overcome.

With this object in view the invention provides an improved instrument in which a mirror is held in fixed or deinite relation to the eye-piece and the light-supply and the illuminated area is caused to fade across the retina by intercepting the light path. The invention thus provides improved means for 'retinal illumination in making shadow tests, in which the light-supply and mirror may remain in a definite or fixed relation during a test, so that the necessity of mounting the mirror so it may be tilted and so that it may be rotated to angularly vary the a-Xis about which it moves. rFherefore, the mirror, when once fixed or adjusted into correct relation with respect to the eye-piece, will remain so and will not vary by reason of any inaccuracy in its mounting or wear of the mirror mounting.

The invention further designs to improve the construction and operation of instruments in retinoscopy and ophthalmoscopy.

The invention consistsin the novel features hereinafter set forth and more particularly defined by claims at the conclusion hereof.

In the drawings: Figure 1 is a view, partly in side elevation and partly in section, of an instrument embodying the invention. Fig. 2 is a horizontal section taken through the center of the focal-tube. Fig.

The improved instrument may be adjust-.

ably mounted upon any suitable base or support 12. A post 13 is slidably and adjustably mounted in the base, so that the elevation of the instrument may be varied as desired. At one end, a suitable chin-rest 14: is carried by the frame and a head-support 15 is provided above the chin-rest for the convenience of the patient. A focal-tube 16 is secured to standard 17 which is adjustably mounted in the base, as well understood in the art, so that its elevation may be varied to suit the patient. A. suitable eyepiece 18 is mounted in the outer end of the' focal-tube 16, this piece being formed to fit snugly around the eye, to exclude light from the outside. A slidable frame or bar 19 is mounted on the post 17, being connected thereto by a dove-tailed rib 2O fitting in a correspondingly shaped groove in the post. A pinion 21 operatively connected to thumbwheels 22 and journaled in the post, meshes with a rack 23 on the supporting-bar 19 to adjust the latter longitudinally of the focaltube. Bar 19 serves to support a mirror or reflect-or 24 and a light-tube 25. A bracket 2G is secured to the under side of bar 19 and has secured thereto a ring 27 around which the light-tube 25 is removably fitted, and a source of light, such as an incandescent lamp 28, is disposed within the light-tube. The latter extends angularly upward to project light onto the mirror 24 and its upper end is provided with a condenser-lens 29.

The mirror 24 is mounted at such angle with respect to the light-supply and the focal-tube, that it will reflect the light-rays through the focal-tube to the eye piece 18 and illuminate the interior of the eye andl the retina. A conoidal end-piece 30 cuts oif the dispersed light from the focal-tube and has an opening in its rear end for the light rays projected by the mirror. The mirror 24 consists of a plate of glass having its back silvered with the exception of a small central portion and the plateis secured to a metallic disk or holder 3l, which is provided with lugs 3Q adapted to receive screws 33 for securing the mirror in stationary or delinite relation to the light-supply. Screws 33 extend through a shell which is secured to a back-plate which is scoured to the bar 19. lWhile these screws secure the mirror in delinite relation, they also permit the mirror to be set into correct relation to the eye-piece. tesultantly, the mirror and lighttube are both carried by the adpistable bar 19 and-remain in definite relation to one another. `Flats 35 is provided with a sightopening 3G back et a peep-hole 37 formed vin the back-plate 31 of the mirror, so that by placing his eye at the side opening 36, the operator can-look through the peep-hole S7 and the unsilvered portion ot the mirror to examine the eye at the eye-piece 18, on which light will be projected by the mirror. i In shadow tests, refractive errors are de- Atected by causing the light on the retina to yniinated area ot' the retina.

ya slide Sli-mounted to travel across the lightpath between the condenser lens 29 and the mirror Q4: and across an opening ll() in a revoluble shutter-carri er t1 which is mounted at the lower end of a tube d2 through which the light passes from the light-supply tothe mirror. Resultantly. as the slide is moved across opening d0, the light will be progressively out olf from the mirror to correspondingly reduce the illuminated area on the eye. Slide 39 is provided with a lingerpiece d3, whereby it may be pushed inwardly to close oienine l() ao'ainst the torce ot' a `pair of springs Lid, which are mounted in i spring-barrels -t on the shutter-carrier all. I Rods 4 6 are secured to the slide on the carrier 41 and engage the springs. A screw 4-7 serves as an opposing abutment for each of `the springs ftd. ln order to produce the desired effect upon the eye, it is necessary that this slide shall be capable et quick back and `foi-th oaeration and b i arovidino' s rings tor operating slide in one direction, the illumina-ted area of the eye, will be progressively increased as the pressure upon the V slide is released by the operator; f By this means, the slide may be quickly manipulated as desired to produce the shadow effects deosmosi si i'ed in determining refractive errors of the eye without tilting the mirror. rihe slidecarrier /l-l is rotatably mounted in the end ot the tube ft2, having a tace-plate el which is held against the bottom i8 ot tube Ll2 by a washer t9 and screws 50. ltesultantlyj the shutter and its carrier may be rotated to cause the shutter to progressively cutotl' the light-supply in different meridians. A suitable scale 51 is secured to the shuttercari'ier el-l so that the angular position of the slide and the meridian across which the light is being cut oil or vanishes on the illuminated area of the retina of the eye7 will be indicated to the operator.

ln operation of the improved iediinoscope7 the eye of the patient is placed at the eyepiece 18 and the operator places his eye at the sight-opening 3G. The light-rays -from the light-supply 28 will be directed through opening d0, tube d3 on the carrier @il onto the mirror, and projected by the mirror through the focal-tube 16 into t-he retina oit the patientls eye at the eye-piece 1S. To make a shadow-testn the operator will press the linger-piece l?) of shutter-slide 89 inwardly, which will cause the slide to progressively eut oit the light as the shutter obstiucts openings Ll0, thus causing the light rays to be correspondingly cut ott troni the mirror to illuminate an area corresponding to the position ot the slide across opening d0. The shutter will be retracted by springs l-y-l; and cause the illuminated area to piogiessively increase as the shutter passes into its open position. rl`he shutter may be operated as frequently as desired to produce the desired eiteet upon the illuminated area of the eye. ln order to cause the illuminated area to progressively increase and decrease across ditlerent planes, the slide-carrier Lll may Je rotated to any angle desired and the nieridiaii iii which the shutter is moving and the corresponding meridian at which projected light in the eye will be cut oli' will be accurately indicated on the scale 51.

rlhe invention thus provides an improved retinoscope, in which the light-supply and mirror may remain in definite iXed relation to each other, while a shadow test77 is being made and the necessity of providing a tiltable and rotatable mirror, likely to aitect the accuracy of the test, is avoided, since slight variation due to wear of the parts in a tilting mirror will affect the accuracy of the test, while with the intercepting shutter, the accuracy of the test will not be a'llected.

rlhe improved instrument may also be used as an ophthalmoscope and for this purpose a strong plus lens is inserted in the focal-tube at 67 and a battery ot lenses to correcttlie amathropia, when used as a` retinoscopeoi ophthalmosoope, is provided. ln instruments ot this character, it is desirable that the patients eye should be directed to a straight distant object and not obstructed by some part of the instrument. F or this purpose a rotatable lens-carrier is mounted at each side of the focal-tube to rotate in a plane as nearly as possible parallel to the axis of the focal-tube. A lens-carrier GO is journaled on a stud 6l projecting laterally from the focal-tube and is held on the stud by a screw 62 and a friction-Washer 63, which frictionally holds the lens-carrier in assigned position. At the other side of the focal-tube, a similar lens-carrier 6% is similarly mounted. Each of these lens-carriers is provided with an inwardly extending flange or Wall in which the lenses are held to extend transversely to the axis of the focal-tube and these tlanges are adapted to travel through an opening GG in the tube adjacent the eye-piece 1S. By rotating the lens-carriers, any lens of the battery may be brought into the focal-tube and usually' one of the openings in the flange of each lens-carrier is not provided With a lens, so that the instrument may be used as an ophthalmoscope Without any lens of the battery being interposed in the light path between the patients eye and the mirror. A suitable opening 67 is formed in the top of the focaltube through which an object-lens mav be inserted to form an image of the retina of the eye. rlhe instrument thus provides improved means for adjustably carrying a battery of lenses which does not interfere With the view of the free eye of the patient.

The invention is not to be understood as restricted to the details shown and described, since these may be modified Within the scope of the appended claims, Without departing from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is:

l. ln an optical instrument, the combination of a light-supply, a mirror for projecting light from the supply, and means mounted to move across the light-path to progressively vary the area of the eye illuminated by the mirror.

2. ln an optical instrument, the combination of a light-supply, a mirror for projecting light from the supply, and means mounted to move across the light-path to progressively vary the area of the eye illuminated by the mirror While the light-supply and mirror are in xed relation to each other.

3. In an optical instrument, the combination of a light-supply, a mirror for projectingl light from the supply, and rotatably supported means mounted to move across the light-path to progressively vary the area of the eye illuminated by the mirror.

4. In an optical instrument, the combination of a light-supply, a mirror for projecting light from the'supply, and rotatably supported means mounted to move across the light-path to progressively vary the area of the eye illuminated by the mirror While t-he mirror and light-supply remain in relatively fixed relation to each other.

5. ln an optical instrument, the combination of a light-supply, a mirror for projecting light from the supply, and means mounted to move across the light-path between the supply and the mirror to progressively vary the area of the eye illuminated by the mirror.

6. In an optical instrument, the combination of a light-supply, a mirror for projecting light fgrm the supply, and means mounted to move across the light-path between the supply and the mirror, to progressively vary the area of the eye illuminated by the mirror While the light-supply and mirror are in fixed relation to each other.

7 ln an optical instrument, the combination of a light-supply, a mirror for projecting light from the supply, and rotatably supported means mounted to move across the light-path between the supply and the mirror, to progressively vary the area of the eye illuminated by the mirror.

8. ln an optical instrument, the combination of a light-supply, a mirror for projecting light from the supply, and rotatably supported means mounted to move across the light-path between the supply and the mirror, to progressively vary the area of the eye illuminated by the mirror While the mirror and light-supply remain in relatively xed relation to each other.

9. In an optical instrument, the combination of a light-supply, a mirror for projecting light from the supply, and a shutter slidably mounted to move back and forth across the light-path, to progressively vary the area of the eye illuminated by the mirror.

l0. In an optical instrument, the combination of a light-supply, a mirror for projecting light from the supply, and a shutter slidably mounted to move back and forth across the light-path, to progressively vary the area of the eye illuminated by the mirror While the light-supply and mirror are in fixed relation to each other.

ll. In an optical instrument, the combination of a light-supply, a mirror for projecting light from the supply, a shutter mounted to move back and forth across the light-path to progressively vary the light of the eye illuminated by the mirror, and a rotatable support on which the shutter is mounted.

l2. In an optical instrument, the combination of a light-supply, a mirror for projecting light from the supply, a shutter mounted to move bac-k and forth across the light-path to progressively vary the area of the eye illuminated by the mirror While the mirror lOO llO

and light-supply remain in relatively lifted relation to each other, and a rotatable support on which the shutter is mounted.

i3. in an optical instrument,the combination ot a light-supply, a mirror for projecting light troni the supply, and a shutter slidably mounted to move back and torth across the light-path between the supply and the mirror` to progressively vary the area ot' the eye illuminated by the mirror.

l-l. ln an optical instrument, the combination of a light-supply, a mirror for projecting light :trom the supply, shutter slidably mounted to move bach and orth across the light-path between the supply and the mirror, to prog"essivolyyvary the area ot the eye illuminated by the mirror while the light supply and mirror are in tired relation to each other.

ln an optical instrimient, the combination ot a linjht-supj'ily, a mirror for projecting/ light 'from the supply, a shutter mounted to move basl; and forth across the light-path between the supply and the mirror, to progressii-fely vary the area the eye illi'iminated by the mirror, and a rotatable support on which the shutter is mounted.

lo. in an optical instrument, the combination ot a light-supply, a mirror tor projecting li ght trom the supply, a shutter mounted to more baelr and `torth across the light-path between the sugply and the mirror, to pro- `efressively vary the area oit the eye illuminated by the mirror, while the mirror and light supply remain in relatively lined relation to each other, and a rotatable support on u'hieh the shutter is mounted.

iT. ln an optical instrui'nent, the combination olf a light-supply, a mirror for projecting; iglt troni thesupply, rotatably supi i ed means mounted to move across the th to progressively vary the area ot ya illuminated by the mirror, and means tor indicating;l the meridian in which said means moves across the light-path.

lo. ln an optical instrunient,the combination of a light-supply, a mirror i'or projecting; light from the supply, shutter slidably mounted to move back and torth across the light-path to pro ssively vary he area ot the eye illuniinated by the mirror, a rotatable support on which the shutter is mounted, and means tor indicating the angular position ot' the shutter.

it). ln an. optical instrument, the combination of a light-supply, a mirror for project- .ingh light trom the supply, means mounted to move across the light-path to progressively vary the area ot the eye illuminated by the mirror, and a spring for operating said means in one direction.

20. ln an optical instrument, the combination a light-supply, a mirror for projecting light from the supply, a shutter mounted to move across the light-path between the supply and the mirror, to progressively vary the area oit the eye illuminated by the mirror, a rotatable support on which the shutter is mounted, and a spring` `for operating said shutter in one direction.

2l. ln an optical instrument, the combination of a, light-supply, a mirror for projecting` light from the supply, a light-tube eX- tendingg singularly downward from the mirror, and means mounted to move across the light-path to progressively vary the area ot the eye illuminated by the mirror.

ln an optical. instrument, the combination ot a light-supply, a mirror for projecting' light 'from the supply, a light-tube extending angularly downward from the mirror, and a shutter mounted to move back and forth across the path of light passing through said tube. h

255. ln an optical instrument, the combination ot a light-supply, a mirror for projecting` light trom the supply, a. light-tube extendingl angnlarly downward from the mirror, a shutter mounted to move back and forth across the path ot light passing through said tube, and a rotatable support the shutter.

ln an optical instrument, the comblnation ot a` supporting-trame, a focal-tube, an eye-piece at one end of said tube, rotatable lens-carriers having their axes extendino laterally and outwardly with respect to the local-tube at such angles that they will be in close proXimity to the tube, inwardly extending` means on the carriers respectively 100 for holding' lenses in over-lapping relation and in operative relation to the focal-tube, the latter extending between the carriers and substantially to the lens-holding` means, and

inwardly extending' means for the carriers 105 connected to the ilocal-tube between then EARL il". Ell-@TVN lllitness-es:

Flinn Grantor-r, llrrnnlv C. Pn'rnnsnn.

Copies of this patent may be obtained for 'ave cents each, by addressing" the Commissioner of Patents, Washington, D. C. 

